It is extremely important to select the correct adhesive to receive the maximum efficiency out of the selected product.
There are a number of adhesive applications that must be considered. A shell core may employ an adhesive immediately after the core is removed from the box (the core will be extremely hot and this is not the preferred time to apply an adhesive), the core may be "warm to the touch" and when the core is sufficiently cool. It is important to realize that there is not a single adhesive for all of these applications.
When a shell core is extremely hot it is very difficult to apply an adhesive that will create a sufficient bond to maintain the strength at the joint of the core. The only adhesive that will meet this application is a water based core adhesive that is designed for "thermal curing" (oven curing). The product that we recommend for this application is Red Chief. However, it very important to realize that this is not the best application time for any core adhesive.
The next application that can be discussed concerns the use of an adhesive when the shell core is "warm to the touch". In this application, a sodium silicate based core adhesive is preferred. These adhesives will take advantage of the elevated temperature of the shell core to enhance the "curing characteristics". The application of a water based adhesive (discussed above) will not have sufficient temperature to develop the complete bonding mechanism and the solvent based adhesives set-up too fast. The adhesive that is recommended for this application is Green Hornet.
In order to get the maximum curing characteristic out of an adhesive at "ambient temperatures" is a solvent based core adhesive. Shurstick 306 is the ideal product for this application. It will develop tensile strength rapidly and will allow ease of handling of the assembled core. As a result of these discussions, it is extremely important to understand that the correct core adhesives must be selected for the various applications.
For Green Sand Metalcasting
Hill and Griffith GREEN HORNET™ Core Paste is formulated with organic and inorganic binders, fillers, suspension agents and water. GREEN HORNET™ Core Paste provides good strength in relatively short periods of time and exhibits excellent storage life.
Hill & Griffith offers RED CHIEF, a ready to use Core Paste formulated to suit a variety of foundry applications. Use with fine, medium or coarse sands. Can be applied to Blank Sand, Oil Sand, No Bake and Shell Mold Operations.
SHURSTIK 306 is a proprietary blend of solvents, fillers, adhesives and suspension agents. SHURSTIK 306 is a product designed to meet the increasing demands of higher production rates and efficiency. SHURSTIK 306 exhibits excellent strength with short periods of set time.
More details on these core paste products:
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The Hill and Griffith Company's green sand metalcasting foundry supplies help achieve the EPA's M.A.C.T. standards and reduce Benzene emissions. Our variety of environmentally sound release agents, coatings, partings, lubricants, core oils and specialty products will help you meet your metal casting's needs. We're known for our hands on approach. Let us visit your plant and recommend products that suit your needs.
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